董先锋,王涛,卢少勇,卢洪斌,李嘉欣,李响,肖利萍.污染浓度对多级人工湿地-塘系统处理微污染河水中COD的影响[J].环境科学学报,2021,41(9):3563-3577
污染浓度对多级人工湿地-塘系统处理微污染河水中COD的影响
- Concentration effect on the treatment of micropollutant in river with multistage constructed wetland-pond systems
- 基金项目：国家科技支撑计划项目（No.2014BAC09B02）；科技基础性工作专项重点项目（No.2015FY110900-06）
- 董先锋
- 中交(天津)生态环保设计研究院有限公司, 天津 300450
- 王涛
- 1. 中国环境科学研究院, 环境标准与风险评估国家重点实验室, 国家环境保护湖泊污染控制重点实验室, 国家环境保护洞庭湖科学观测研究站, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012;2. 辽宁工程技术大学, 环境科学与工程学院, 阜新 123000
- 卢少勇
- 中国环境科学研究院, 环境标准与风险评估国家重点实验室, 国家环境保护湖泊污染控制重点实验室, 国家环境保护洞庭湖科学观测研究站, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012
- 卢洪斌
- 1. 中国环境科学研究院, 环境标准与风险评估国家重点实验室, 国家环境保护湖泊污染控制重点实验室, 国家环境保护洞庭湖科学观测研究站, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012;2. 北京师范大学, 水科学研究院, 北京 100875
- 李嘉欣
- 中国环境科学研究院, 环境标准与风险评估国家重点实验室, 国家环境保护湖泊污染控制重点实验室, 国家环境保护洞庭湖科学观测研究站, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012
- 李响
- 1. 中国环境科学研究院, 环境标准与风险评估国家重点实验室, 国家环境保护湖泊污染控制重点实验室, 国家环境保护洞庭湖科学观测研究站, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012;2. 辽宁工程技术大学, 环境科学与工程学院, 阜新 123000
- 肖利萍
- 青岛理工大学, 环境与市政工程学院, 青岛 266033
- 摘要：针对微污染水水质不稳定，CODMn波动较大的问题，本研究构建了3套中试规模的以"前置生态氧化塘、两级水平潜流湿地和表流湿地为核心、后置沉水植物塘"为工艺的多级人工湿地-塘组合系统（处理水量230 L·d-1，分别命名为S1、S2和S3）.在3种进水浓度条件下（原水、稀释2倍和稀释1.3倍后的水体，分别作为S1、S2和S3系统的进水），考察了3套湿地-塘系统各单元对实际微污染河水中CODMn的处理效果，并采用高通量测序等方法解析了S1系统湿地单元微生物群落分布特征.研究结果表明，3套系统的平均出水COD较进水有着非显著的升高，从升高的程度来看，S2>S3>S1.污染浓度相对最高、运行时间最长的S1系统对COD有着更好的净化效果.相较于S2系统，S3系统更高的进水浓度有利于COD去除.S1和S2系统的二级水平潜流湿地较其他单元有着较好的COD去除作用，平均去除率分别为18.60%和26.52%.S3系统的表流湿地较其他单元有着较好的COD去除作用，平均去除率为8.92%.微生物群落分析结果表明，S1系统的一级、二级水平潜流湿地中细菌丰度和多样性沿程提高，两个单元所富集的相同优势菌群包括α-变形菌纲、γ-变形菌纲和拟杆菌纲，与COD降解有关的菌属分别包括unclassified_f__Burkholderiaceae、unclassified_c__Alphaproteobacteria、norank_f__Blastocatellaceae和norank_f__Saprospiraceae、红细菌属.表流湿地中细菌丰富度进一步升高，但生物多样性有所减少，其中蓝菌属和norank_c__Actinobacteria可能与表流湿地出水COD升高有关.本研究为大型河口湿地-塘复合生态系统处理微污染地表水时工作重心由浓度削减向污染物释放控制的转移提供了宝贵的工程经验.
- Abstract：The quality of micropolluted water is unstable, and its CODMn concentration fluctuates greatly. To solve these problems, three pilot-scale multistage wetland-pond systems (230 L·d-1, named S1, S2 and S3) were constructed: a front ecological oxidation pond, a two-stage horizontal subsurface-flow constructed wetland with a surface-flow constructed wetland as the core, and a postsubmerged plant pond. The effect of each unit on the treatment of CODMn in actual micropolluted river water was investigated by applying three concentration conditions (raw water, raw water diluted 2 times, and raw water diluted 1.3 times) as the influent water of the S1, S2, and S3 systems. The distribution characteristics of the microbial communities in the constructed wetland units of the S1 system were analyzed via high-throughput sequencing technology. The results showed that the average effluent CODMn in the three systems was nonsignificantly higher than that of the influent. The CODMn effluent concentration followed the order S2>S3>S1. The S1 system, which had the highest contaminant concentration and the longest operation time, had a better COD purification effect than the S2 and S3 systems. Compared with the S2 system, the S3 system had a higher influent concentration, which was beneficial for COD removal. The second-level horizontal subsurface-flow constructed wetlands of the S1 and S2 systems achieved better COD removal than the other units, with average removal rates of 18.60% and 26.52%, respectively. In the S3 system, the surface-flow constructed wetland had better COD removal than the other units, with an average removal rate of 8.92%. The results of the microbial community analysis showed that the bacterial richness and diversity in the first-level horizontal subsurface-flow constructed wetland and second-level horizontal subsurface-flow constructed wetland of the S1 system increased along the treatment line. The predominant bacterial classes enriched in both units included Alphaproteobacteria, Gammaproteobacteria and Bacteroidia. The genera related to COD degradation included unclassified_f__Burkholderiaceae, unclassified_c__Alphaproteobacteria, norank_f__Blastocatellaceae, norank_f__Saprospiraceae and Rhodobacter. In the surface-flow constructed wetland, the bacterial richness increased, but the diversity decreased. Cyanobium_PCC-6307 and norank_c__Actinobacteria might have been associated with the elevated effluent COD concentration in the surface-flow constructed wetland. This study provides valuable engineering experience supporting the shift in focus from concentration reductions to pollutant release controls in the treatment of micropolluted surface water by large-scale integrated constructed wetland-pond ecosystems.
